γδ T cells function at the interface between the innate and adaptive immune systems and have well-demonstrated roles in response to infection, autoimmunity, and tumors. A common characteristic of these seemingly disparate conditions may be cellular stress. Very few verified ligands for γδ T cells have been identified and these have been largely intact self-proteins with no obvious common structure. In addition, no traditional MHC-restricted recognition of ligands has been demonstrated for γδ T cells. Thus, the conditions under which ligands for γδ T cells are induced or exposed remain largely undefined.